1. Field of the Invention
The invention relates to electronic device security. Particularly, the invention relates to a method for the secure storing of program state data in an electronic device.
2. Description of the Related Art
In a world where all computer programs and applications are potential targets for manipulation it is necessary for users to be able to rest assured that the programs they are using remain as they were when originally installed or downloaded. There is a risk that the programs are replaced with a program with similar look-and-feel, which, however, collects and leaks information, for example, to the Internet. The software and digital media vendors also realize the risks involved in unauthorized distribution and product tampering. The risks are particularly prominent in the cases where a computer program is used to control real-life assets.
Increasingly many mobile devices and computing devices are being provided with trusted environments, that is, secure program execution environments. The trusted environments are used to run applications which handle device specific or imported secrets. Data in the trusted environment may be used to implement digital rights management and copy protection.
However, the problem in existing trusted environments is that programs and data are stored, up-dated and read in co-operation with the owner of the trusted environment. The owner may be the device manufacturer, a service provider (xSP) or a network operator. Any new features and programs added require verification from the owner of the trusted environment. It would be beneficial to be able to have a solution which enables third parties to take advantage of the trusted environment to provide a basis for a plethora of trusted third party programs.